The year was 1867. A farmer who had been napping under a tree, spotted a relatively puny golf ball-sized rock. The finder can be forgiven for not realizing that the 21.25-carat shiny light-golden lump was a diamond. After all, diamonds were colorless, right? So when his wife gave the brownish-yellow stone away to a curious neighbor who sent it to Johannesburg for testing, only then was it identified as a diamond. After being cut to a 10.73-carat cushion shape, it was named the Eureka (an interjection meaning “I found it!” often exclaimed after an important discovery) and put on display at the Paris Exhibition of 1868. Now, nearly 150 years after its discovery, the Eureka still remains a prophetic, even if no longer a prodigious, first. Here’s why.
A polished diamond weighing almost 11 carats was boulder-sized by 19th century standards. Gemologist Max Bauer, writing around 1900, wrote that 1 and 2 carat stones were rarities in jewelry stores until the South African diamond rush of 1868. By 1872, all that changed drastically when South Africa’s mines had jumped annual world diamond production tenfold and average sizes had catapulted accordingly. Carat-plus sizes were no longer a dream but a reality—albeit an expensive one. Indeed, just 38 years later, the largest-ever diamond, the Cullinan, weighing 3,106.75 carats, was found near Pretoria.
After a year of planning, the rough was cut in Paris to a 128.51-carat cushion. This was a farseeing decision. Against the advice of his contemporaries, Kunz chose the exact same cutting style for his giant gem as they owners of the Eureka had: a cushion shape. His goal was to emphasize intensity of color as much as immensity of size. Named the Tiffany Diamond, this gigantic cushion cut was to become the most famous diamond on display in America, given feature billing at both the 1934 and 1939 World’s Fairs. Indeed, until jeweler Harry Winston donated the deep-blue Hope Diamond to the Smithsonian Institution in 1958, the Tiffany Diamond was America’s flagship fancy-color diamond.
This history is important because it foreshadows the current boom in fancy yellow diamonds. What did Kunz see in these stones that it took the rest of diamond trade more than a century to discover? And how did his decisions with regard to cutting yellow diamonds anticipate the present day?
From Cape to Canary
In 1940, the last year of his life, F. Scott Fitzgerald wrote, “There are no second acts in American lives.” While that may be so for people, it is decidedly not so for diamonds–yellow diamonds, especially. Here’s why and how.
Did you know that 98% of the world’s diamonds contain nitrogen–which acts, to varying degrees, as a light-absorbing agent? The nitrogen atoms sponge up blue light and make stones appear varying degrees of yellow. These diamonds are classified as 1A and judged for color using two scales: cape and canary.
Cape diamonds (a term adopted after the influx of yellowish diamonds from South Africa’s Cape province in the late 19th century) are the ones most people buy. These are diamonds graded anywhere from slightly to noticeably yellowish on the world-famous GIA D-to-Z color-grading scale, starting roughly at K-color. For years, cape diamonds were considered less desirable and thus used less in jewelry.
Then, around the turn of the 21st century, something momentous happened that gave many cape diamonds a second life as generic canary diamonds: yellow diamonds of pleasing color on a special color-intensity scale from pale and pastel to bright and burning. Unlike cape diamonds which are graded for absence of color on a D (colorless) to Z (tinted) scale, these stones are rated for presence of color, using a five-stage progressive scale, also developed by GIA: 1) fancy light, 2) fancy, 3) fancy intense, 4) fancy vivid, and 5) fancy deep. Instead of cutting these stones into traditional highly brilliant rounds whose glare reduces yellow tint, dealers started cutting them as highly refractive rectangular and square cuts. Suddenly, stones once considered less desirable colorless diamonds had second acts as full-fledged fancy colored diamonds. This innovation allowed thousands of unwanted cape diamonds to become much-wanted canaries.
A True Canary
Besides being a generic term for all yellow diamonds that qualify as fancy color, the term canary has a specific meaning as an ideal yellow color. This secondary meaning has resulted in semantic confusion. Sadly, canary has often been used as a superlative–a usage it was never meant to have. Although experts might agree on the very few stones that merit description as top-of-the-totem canaries, they are careful to pronounce very few stones as worthy of this term. Almost every time when I have asked a colored diamond specialist to show me a stone that embodies his definition of true canary, I have been told they had no such stone and didn’t know of anyone who did.
I took my search for a true canary diamond to Alan Bronstein, a dealer who has amassed the two largest collections of fancy color diamonds in modern history, hoping he would show me the holy grail of fancy yellow diamonds. He showed me a stone that seemed as bright as an ingot on an anvil—pure yellow with maybe just a hint of orange. I can only describe this stone as a “fiery yellow diamond that glowed like a late-afternoon sun,” and leave it at that. Suffice it to say, I can now attest to the existence of canary diamonds as beautiful as any bird of paradise.
Also suffice it to say, true canary diamonds are spotted about as seldom as grails and unicorns. Needless to say, such stones are stratospherically expensive.
Nevertheless, there is a full spectrum of readily available, very affordable fancy yellow diamonds–thanks to the advent of the radiant cut.
For years, cutters have pondered the problem of retaining the diamond’s fabled brilliance while at the same time heightening color. Their solution was very much like the one George Kunz devised to maximize, rather than minimize, color in rough. But modern cutters departed from Kunz by inventing a hybrid that balanced the best aspects of the modern-brilliant and rectangular-to-square shaped cuts. This involved cutting strongly yellowish cape stones with the bottom of a modern modified brilliant and the top of a square or rectangular shape. Square and rectangular tops made light rays travel a greater distance within the stone before being reflected to the eye. As light paths lengthened, color refraction was strengthened. Greater refraction gave greater depth and intensity of color. At the same time, modern-brilliant bottoms assured the great glitter that one expects from diamonds.
This article was written for Worthy by David Federman, the author of The Consumer Guide to Gemstones, Gem Profile: The First 60, Gem Profile 2:The Second 60, and a co-author of The Professional’s Guide to Jewelry Insurance Appraising and The Pink Pearl. As a journalist for Modern Jeweler and JCK magazines for more than 30 years, he helped to create the groundbreaking gemstone treatment disclosure system now used by the industry today. His popular column Gem Profile for Modern Jeweler magazine won more Neal Awards than any feature in the history of the awards.